Growth curve data on an orthdontic measurement

Description

The Orthodont data frame has 108 rows and 4 columns of the
change in an orthdontic measurement over time for several young subjects.

Format

This data frame contains the following columns:

distance

a numeric vector of distances from the pituitary to the
pterygomaxillary fissure (mm). These distances are measured
on x-ray images of the skull.

age

a numeric vector of ages of the subject (yr).

Subject

an ordered factor indicating the subject on which the
measurement was made. The levels are labelled M01
to M16 for the males and F01 to F13 for
the females. The ordering is by increasing average distance
within sex.

Sex

a factor with levels
Male and
Female

Details

Investigators at the University of North Carolina Dental School
followed the growth of 27 children (16 males, 11 females) from age 8
until age 14. Every two years they measured the distance between the
pituitary and the pterygomaxillary fissure, two points that are easily
identified on x-ray exposures of the side of the head.